Side effects of certain antidepressants when used during pregnancy may result in slower motors skills among newborns, according to the findings of a new study.

In research examining prenatal exposure to antidepressants that was published online June 21 in the journal Pediatrics, Australian researchers found significant associations between the use of the medications and poorer motor control among children. However, they note that the findings should be interpreted cautiously.

The study looked at a number of databases, and settled on a systematic review and meta-analysis of 18 studies. According to the findings there was a 22% increased risk that using antidepressants during pregnancy would result in poorer motor outcomes in children.

The findings could be significant, since the study’s authors estimate that about 8.5% to 11% of pregnant women suffer depression. Additionally, pregnant women have been prescribed antidepressants four to 16 times more often in the last decade to 15 years than in earlier years. However, the researchers stressed that more studies need to be conducted to make any causal connection.

“A small increased risk of poorer motor development may exist for children who are exposed to antidepressant medications during pregnancy,” they concluded. “However, the marked methodological variation among studies and the limited control for possible confounds warrants cautious interpretation of these findings.”

Those researchers concluded that women who took antidepressants were twice as likely, on average, to have a child diagnosed with a psychiatric disorder by the age of 16. Most children were diagnosed by the age of eight.

Other prior studies have also warned of a link between prenatal antidepressant use and side effects for the unborn child, including language disorders, birth defects and other serious health concerns that raised questions about whether antidepressants are safe during pregnancy.

Researchers warn that pregnant women should not stop using their medication until they speak to their doctor. One study indicated the benefits of SSRI treatment during pregnancy outweighed the risks, with that study’s authors indicating that the benefits of antidepressants are especially important among women with certain psychiatric disorders that may not be treated by other means.

Antidepressants have been increasingly used during pregnancy for the past few decades. Researchers indicated approximately 2% to 8% of pregnant women are taking antidepressants. SSRIs are the most commonly prescribed.